The present invention relates to an improved dust collection system and, more particularly, relates to a dust collection system that more effectively collects dust or other particulate matter generated by a driven member of a cutting or abrading device and directs the matter away from a workpiece support surface of the device. The present invention also relates to devices including a driven member for cutting or abrading a workpiece of wood, metal, or another material and that incorporate the improved dust collection system of the present invention. The improved dust collection system of the present invention may be advantageously incorporated into any device having a driven cutting or abrading member that generates dust or other particulate matter on contacting a workpiece of wood, metal, or another material.
A saw blade separates wooden workpieces into separate portions by removing a thin region of the workpiece to free the portions. The thickness of the region removed by the saw blade corresponds to the saw blade thickness or xe2x80x9ckerfxe2x80x9d. Saw blades, whether of the circular, continuous band, elongate, or bayonet type, include a series of blade teeth separated by recesses known as gullets. As the blade teeth pass through the workpiece, each tooth removes a portion of the workpiece into a fine particulate matter commonly referred to as sawdust. The sawdust collects in the gullets of the portion of the saw blade disposed within the cut in the workpiece, and the gullets transport the sawdust out of the cut, whereupon it is released into the atmosphere. If the sawdust is not efficiently conveyed out of the cut in the workpiece by the gullets, the quality of the cut is compromised. The blade teeth may, in the extreme, be unable to advance further into the workpiece and the saw blade will experience a jam. Significant effort is put into efficiently designing saw blades to quickly remove material from workpieces and effectively convey sawdust out of the cut in the workpiece.
The natural result of efficient saw blade design is the generation of significant amounts of sawdust during cutting operations. The sawdust may obscure the saw operator""s view of the workpiece and also may require the operator or his assistants to spend significant time cleaning the shop or job site to remove the sawdust after completing the cutting operation. If the saw is of the portable type and is used within a living or work space such as the home or office, generation of sawdust is particularly problematic and may require a significant and immediate clean-up effort. Chop saws and miter saws, for example, commonly are used in existing homes to cut crown and other molding during renovation and remodeling. Such saws typically include quickly rotating, aggressive circular saw blades that may generate substantial volumes of dust within the home. Thus, there remains an ongoing effort to design chop saws, miter saws, and other woodworking saws, for example, with dust collection systems to minimize the dispersal of sawdust into the atmosphere.
An example, of a miter saw incorporating a known dust collection system is the Delta(trademark) Model No. 36-210 10xe2x80x3 Compound Miter Saw (xe2x80x9cthe Delta Sawxe2x80x9d). As shown in FIG. 5, the Delta saw 10 is of a conventional design and includes a table 12 rotatably mounted on a stationary base 14 including two side portions 16a, 16b. The rotatable table 12 includes a primary workpiece support surface 18, which is flanked by the paired secondary workpiece support surfaces 20a, 20b of the side portions 16a, 16b, respectively. A one-piece workpiece fence 24 is secured to the secondary support surfaces 20a, 20b and is disposed across the primary support surface 18. A saw unit 26 is pivotally mounted to a pivot assembly 28 that is connected to the rotatable table 12. Thus, as the rotatable table 12 is rotated from the 0xc2x0 miter angle position shown in FIG. 5, the saw 10 may execute miter cuts on a workpiece disposed on the primary and secondary workpiece support surfaces 18, 20a, 20b and against the support surfaces 30a and 30b of the one-piece workpiece fence 24.
The saw unit 26 of the Delta saw 10 includes a cutting unit 32 within which the circular saw blade 34 rotates. A dust transmission pathway is defined within the cutting unit 32 between an inlet 36, to the rear of the saw blade 34, and an outlet chute 38, which is connected to the upper surface of the cutting unit 32. A portion of the sawdust generated by the saw blade 34 enters the inlet 36, and the airflow generated by rotation of the circular saw blade 34 promotes passage of that portion of the sawdust through the dust transmission pathway and out the outlet chute 38. A bag or a vacuum hose system may be attached to the outlet chute 38 to collect the sawdust. The saw may be designed so that the saw blade-generated airflow effectively transmits sawdust that enters the inlet 36 through the dust transmission pathway. Some portion of the generated sawdust, however, is not directed into the inlet 36 during the cutting operation and, instead, is dispersed onto the primary and secondary workpiece support surfaces 18, 20a, and 20b and into the surrounding areas. The fraction of generated sawdust that enters the inlet 36 will depend on such factors as the particular design and rotational speed of the saw blade, the composition of the workpiece, the geometry of the cut, etc. It is possible that a significant fraction of the sawdust will not be directed into the inlet 36 and, instead, will be dispersed onto the miter saw 10 and its surroundings.
Accordingly, a need exists for an improved system for collecting sawdust generated during cutting operations on a miter saw or chop saw. More generally, there exists a need for an improved system for collecting dust or other particulate matter, sawdust or otherwise, in devices incorporating a driven cutting or abrading member that generates dust on contacting a workpiece of wood, metal, or another material. In addition to woodworking miter and chop saws, such devices include, for example, other woodworking cutting devices, sanding devices, metalworking saws, tile cutting saws, and masonry saws.
The present invention addresses the foregoing need by providing an apparatus incorporating an improved dust collection system. The apparatus includes a first member having a first surface including a recess. The apparatus also includes a second member having a driven member mounted thereon. The second member of the apparatus is movable between a first position and a second position relative to the first member, wherein the driven member is closer to the first surface when the second member is in the second position than in the first position. The second member includes a dust collection system having an inlet, an outlet, and an enclosed pathway between the inlet and the outlet. At least a portion of the inlet is disposed within the recess in the first surface when the second member is in the second position.
The apparatus preferably includes a collector positioned at the inlet and which is for receiving dust or other particulate matter generated by the driven member. At least a portion of the collector is disposed within the recess in the first surface when the second member is in the second position. The driven member of the apparatus may be rotatably or otherwise movably mounted on the second member. The driven member may be, for example, a cutting member or an abrading member. As used herein, xe2x80x9ccuttingxe2x80x9d refers to the act of either severing a workpiece into two or more distinct pieces or placing a cut in a workpiece. As used herein, xe2x80x9cabradingxe2x80x9d refers to the act of sanding, grinding, or otherwise wearing away a surface of a workpiece. A non-exhaustive list of possible cutting members that may incorporated in the device of the present invention includes, for example, woodworking saw blades, metalworking saw blades, tile cutting blades, masonry cutting blade, and sanding disks, drums and belts.
In one embodiment of the apparatus of the invention, the apparatus is a miter saw or chop saw, the first member is a base, the first surface is a workpiece support surface, and the second member is the saw""s cutting unit. A circular saw blade is rotatably mounted to the second member. The cutting unit is pivotable relative to the base between the first and second positions. The cutting unit includes a collector positioned at the inlet and which includes a collector inlet. The collector covers a peripheral region of the saw blade and directs a portion of the generated sawdust entering the collector through the collector inlet into the enclosed pathway toward the outlet in the cutting unit. A portion of the collector is received within the recess in the workpiece support surface when the cutting unit is in the second position.
The present invention also is directed to an adjustable support system that may be incorporated into any device having a workpiece support surface. The adjustable support system includes at least one adjustable support member movably mounted to the device. Preferably, an adjustable support member includes a support element having a support surface and one or more sliding members. The one or more sliding members are slidingly received by the device, and a distance between the support element and the device may be varied by sliding the sliding members relative to the device.
The present invention is further directed to an apparatus including a first member including a first surface and a second member that includes a driven member mounted thereon. The second member is movable relative to the first member between a first position and a second position. The driven member is closer to the first surface when the second member is in the second position than in the first position. The second member includes an inlet, an outlet, and an enclosed pathway therebetween, and a collector is provided at the inlet and is movable relative to the second member.
The reader will appreciate the foregoing details and advantages of the present invention, as well as others, upon consideration of the following detailed description of embodiments of the invention. The reader also may comprehend such additional details and advantages of the present invention upon using the invention.